1. FIELD OF THE INVENTION
The present invention relates to a tray assembly for sorting machine, and more particularly to a tray assembly for sorting machine that is used as a tray for sorting when automatically sorting and storing recorded sheets, and which has entry forming means forming successively tray entry portions between trays supported in a stacked condition.
2. DESCRIPTION OF THE PRIOR ART
In a conventional sorting machine, a pair of cylindrical tray entry forming members was disposed on a tray entry side of stacked trays so as to permit formation of tray entry portions successively when recorded sheets were transported. These tray entry forming members were able to move freely either upwardly or downwardly, and could rotate freely around a vertical axis. This rotating motion moved a tray pin supported above or below the tray entry forming member upwardly or downwardly.
FIG. 1 is a side view showing an example of this type of sorting machine and tray. In FIG. 1, reference numeral 1 denotes a sheet feeding portion, and reference numerals 1A and 1B denote an upper and a lower guide plate formed on the sheet feeding portion 1. Reference numeral 2 denotes a recorded sheet sent from a printing apparatus or a copier not shown. This recorded sheet 2 is fed between the guide plates 1A and 1B.
Reference numeral 3 denotes a sheet feed roller driven by a motor 4, and reference numeral 5 denotes a guide roller for feeding the sheet by contacting the sheet feed roller 3. Reference numeral 6 denotes a discharge roller coupled to the sheet feed roller 3 through a belt 7, and reference numeral 8 denotes a guide roller for discharging a sheet 2 by contacting the discharge roller 6. The axis of the discharge roller 6 and the guide roller 8 are supported by a frame 9. This support frame 9 is disposed so it can slide freely along a guide post 10. Reference numerals 11A and 11B denote upper and lower guide plates disposed respectively between the guide roller 5 and the guide roller 8, and between the sheet feed roller 3 and the discharge roller 6. The guide plates 11A and 11B form the sheet transport route 11.
Furthermore, reference numeral 12 denotes a tray entry forming member having a cylindrical form. Reference numeral 13 denotes a rotating axis of the tray entry forming member 12. The top and bottom surfaces of the tray entry forming member 12 are sandwiched slidably by the frame 9. As described below, when the tray entry forming member 12 moves upwardly or downwardly, the discharge roller 6 and the guide roller 8 are moved in combination simultaneously upwardly or downwardly by the frame 9.
In this arrangement, the tray entry forming member 12 is coupled to the rotating axis 13 so as to be slidable only upwardly and downwardly. Moreover, the rail portion not shown on the rotating axis 13 engages in the groove (not shown) along the length of the tray entry forming member 12 so that the tray entry forming member 12 rotates integrally with the rotating axis 13 only when the rotating axis 13 rotates, and is supported while rotating by the rotating axis 13 so as to be slidable upwardly and downwardly.
The reference numeral 12B denotes a spiral groove worked into the outer circumferential surface of the tray entry forming member 12. The top end and bottom end of the spiral groove 12B are formed into a cuneiform shape. Furthermore, the groove 12B is formed to provide one pitch height in the present example between the top surface and the lower surface of the supporting member This spiral groove 12B makes it possible to move a pin 14A on the edge portion on the entry side of the tray 14 upwardly and downwardly.
Moreover, reference numeral 15 denotes a tray rest supporting the trays 14 at a predetermined inclination. The trays 14 are spaced at predetermined intervals by a supporting member 14C disposed at a tray edge 14B and by a pin 14A. The trays 14 are stacked on top of the tray rest 15. Reference numeral 18 denotes a motor that can rotate the rotating axis 13 in one direction and in an opposite direction.
In the arrangement of a sorting machine such as this, when, for example, the tray entry forming member 12 is lowered from its present position so that a tray entry portion 17 is formed at successively lower levels, if first a motor 18 rotates the rotating axis 13 in a clockwise direction as viewed from above, the pin 14A on the tray 14 that is contacting the lower surface of the tray entry forming member 12 will be guided into the spiral groove 12B, and as the rotation continues the pin 14A will be forced upwards. Thereby, when the rotating axis 13 has rotated once this pin 14A will be supported on the upper surface of the tray entry forming member 12, and at the same time, the tray entry forming member 12 will drop along the rotating axis 13 by a distance corresponding to the diameter of the pin 14A. The lower surface of that tray entry forming member 12 will be supported in contact with the pin 14A immediately below, and the tray entry portion 17 will be formed at a position one level lower.
Furthermore, rotation of the rotating axis 13 in an opposite counterclockwise direction will cause the tray pin 14A that is contacting and supported by the upper surface of the tray entry forming member 12 to be guided into the spiral groove 12B, thereby making it possible to lower that tray 14 by one level and to form a tray entry portion 17 in a position one level higher.
The supporting member 14C that supports the trays 14 when said trays are stacked is disposed near the left and right sides of the tray edge 14B. When the tray 14 is moved upwardly and downwardly by the tray entry forming member 12, the supporting members 14C push out or retract like arrows as they slide against one another in response to that movement of the tray 14. The height between the stacked trays at the tray edges 14B in the stacked condition is determined by the height of a protrusion 14D formed on the upper surface of the supporting member 14C.
This stacked height is determined in accordance with the estimated maximum thickness of recorded sheets that will be loaded into the individual trays 14. In recent years, as the demand has risen for comparatively greater volumes of sheets to be stored in the tray 14, the conventional shape and construction of the supporting member 14C have resulted in many problems.
In particular, with the increasing speed of recording processing the noise of the shock generated when supporting members 14C push out or retract together, when only a small volume of sheets is stored, has increased in loudness to the extent that it has become necessary to suppress such noise to allow for the use of such Office Automation equipments inside offices.
Another problem has been the propensity for sheets to jam due to the tapering of the interval between the tray edges with respect to the interval at the tray entry portion.